Methicillin-resistant staphylococci lead to serious nosocomial and community-acquired infections in an increasing frequency. Phenotypical heterogeneous drug resistance to antistaphylococcal beta-lactam antibiotics affects the results of susceptibility testing; and routine oxacillin disk diffusion tests often fail to detect heterogeneous methicillin-resistant staphylococcus populations. In the present study, 100 clinical isolates of Staphylococcus aureus and 100 clinical isolates of coagulase-negative staphylococci (CoNS), which were detected to be methicillin-resistant in Phoenix bacterial identification and antibiogram system (BD), were studied. In order to screen meticillin resistance, a disk diffusion method with oxacillin 1 μg and cefoxitin 30 μg (BD) discs; and E-test containing with oxacillin and cefoxitin (AB Biodisk Sonia, Sweden) strips were performed. The performance of the different methods were determined with the positivity of mecA gene. It was found that the results of disk diffusion test and E-test for oxacillin and cefoxitin in S. aureus isolates were consistent with mecA positivity. It was also observed that the results of tests, apart from E-test for cefoxitin, was consistent with mecA positivity in CoNS isolates.